Laser sintering is a process involving the construction of a three-dimensional article by selectively projecting a laser beam having the desired energy onto a layer of particles. When coupled with computer aided design apparatus, selective laser sintering is an effective technique for producing prototype as well as mainstream production articles.
Sintered porous polymeric articles are currently constructed by traditional heat sintering processes. Traditional heat sintering processes include fabricating a mold having the desired shape of the article to be produced, filling the mold with powder, heating the mold to sinter the powder particles therein, cooling the mold, and removing the formed article. The requirement of a mold in traditional sintering processes can be a limiting factor in the production of prototype articles as well as articles with complicated shapes. The need to construct a mold can make prototype development expensive and time consuming. Moreover, molds are limited to some extent by the structural complexity of the article to be produced and often require the use of release agents for effective removal of the article from the mold. Release agents are generally undesirable for applications where purity or cleanliness of the produced article is of importance.
With continuing advances in imaging and computer aided design, increasingly complex articles are being developed for production. Reconstructive implants and prosthetic devices, among other areas, have benefited from such advances leading to the design of implants unique to the individual needs of patients. Computer imaging such computed tomography (CT), for example, can permit the design of a custom reconstructive implant operable to match the physical parameters of an individual patient. Nevertheless, due to the limitations of traditional mold sintering processes discussed above, actual fabrication of a porous sintered implant having a complicated or custom shape can be difficult or impracticable.